The present invention relates to telecommunications systems and in particular to telecommunications systems in which remote subscriber stages are used.
Often in telecommunications networks remote subscriber stages (RSS) are used to move some of the switching and concentration functions closer to the subscribers. Typically, one RSS can handle approximately 2000 subscribers.
The requirements for number portability in telecommunications networks increases as people move more often. Also, it is desirable to be able to move groups of subscribers fast, to minimize the work and the disturbance in the network. Groups of subscribers may have to be moved, for example, when a node in the network is being replaced. It is also desirable to be able to move groups of subscriber temporarily when an exchange or an RSS is out of service.
Solutions currently exist for number portability in networks when the subscribers are connected to a local exchange, either directly or via a connection node. Co-pending U.S. patent application Ser. No. 08/733,390 describes a solution in which a telecommunications network comprises an address table in which the number of each subscriber is linked to the identity of the exchange to which the subscriber is connected.
European patent application EP 0 738 093 A2 describes an address node in a telecommunications network linking the logical number of a subscriber to the number denoting a physical connection. Thus, when a subscriber moves, only the number to the physical connection has to be changed in the table, while the subscriber""s logical number may be kept.
It is known how to change the numbers of subscribers belonging to the same number series.
None of the above mentioned solutions solve the problem of moving a lot of subscribers connected to an RSS.
It is an object of the present invention to enable the moving of many subscribers in a telecommunications network to another exchange, irrespective of their telephone number.
It is another object of the invention to enable the efficient handling of subscribers in a remote subscriber stage.
It is another object of the invention to enable the moving of many subscribers in a telecommunications network to another exchange without having to change their telephone numbers.
It is yet another object to enable the moving of many subscribers in a telecommunications network fast and in one operation.
It is still another object to minimize the disturbances in the network when moving many subscribers in a telecommunications network.
These objects are achieved according to the invention by an address registration means for use in a telecommunications network in which subscribers are connected to remote subscriber stages, said remote subscriber stages being connected to local exchanges, comprising a first table providing information for subscribers connected to an RSS, about the RSS to which each subscriber is connected, and a second table providing information about the local exchange to which each RSS is connected.
An RSS, with all subscribers connected to is, is moved from a local exchange to another local exchange by changing the table entry for this RSS in the second table.
The address registration means may be comprised in a supervision node monitoring the state of all local exchanges connected to it. If one local exchange fails, the supervision node may initiate the move of one or more RSSs connected to this local exchange to another local exchange.
The invention offers the following advantages: A large number of subscribers connected to an RSS can be moved efficiently by moving the RSS to another local exchange. This may be used, for example, to move subscribers between operators. With the solution according to the invention, standby exchanges may be used for important subscribers, such as the police to make connections to these subscribers more reliable.